docs(changelog): note the model-download fix under beta.19 (#1548)

Author: jaylfc

CHANGELOG.md

@@ -16,6 +16,9 @@ Versions follow semver beta: `1.0.0-beta.N`, bumped on each dev->master promotio
 ### Changed
 - Office Suite is now Office Studio, and it is a real office suite. Write is a full rich-text word processor (bold/italic/underline, headings, lists, links); Calc is a real spreadsheet with a formula engine (cell references, SUM/AVERAGE/MIN/MAX/COUNT/IF), multiple sheets, sort/filter and CSV import/export; and Slides is a real presentation editor with layouts, images, a fullscreen present mode and PDF export. All three save to your cluster (#1565, #1568, #1569).
 
+### Fixed
+- Models: downloading a model actually downloads it now. The Models app was showing a fake progress bar and a false "installed" state without ever contacting the backend, so the model vanished on reopen and no file was fetched. Download now calls the real backend, shows true progress, reflects the backend's installed state, and surfaces a real error with a Retry button on failure. Reported by @mandresve (#1548).
+
 ## [1.0.0-beta.18] - 2026-07-03
 
 ### Fixed